Mesh pouch for medical implant

ABSTRACT

An implementation of a mesh pouch includes a mesh wall that defines an enclosure having an opening at an end. The mesh wall includes a plurality of pores, each of which is at least 70 microns in diameter. The mesh pouch further includes a drawstring configured to close the opening when drawn so as to prevent the surgical implant from leaving the enclosure. The mesh pouch may further include a strand extending from the mesh wall and a needle attached to a terminus of the strand. The strand may be configured to tighten the mesh wall around the surgical implant when pulled.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. applicationSer. No. 16/186,785, filed on Nov. 12, 2018 (now U.S. Pat. No.10,363,127), which claims the priority benefit of U.S. ProvisionalPatent Application 62/585,402, filed on Nov. 13, 2017. Theabove-referenced documents are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

The present disclosure relates generally to mesh coverings for implantsand, more particularly, to a mesh pouch for an implant.

BACKGROUND

The present disclosure relates to field of surgically implantabledevices. Aspects of this disclosure specifically relate to the supportand stabilization of a breast prosthesis using bioabsorbable, flexiblemesh pouches.

Synthetic implants composed of silicone or saline are commonly used inboth breast augmentation and reconstruction, but in both cases the softtissue envelope alone is sometimes insufficient to keep the implant inthe appropriate location. Further, in many cases it is difficult toachieve or maintain an anatomically appropriate breast shape when around implant is used. Due to these deficiencies in native tissue, arevision surgery is sometimes needed to reshape, reposition, lift, orotherwise modify the implant and/or periprosthetic tissue. A revisionsurgery could be avoided if an additional, shaping, localizing supportstructure for the breast implant was provided. An internal bra in asling or a hammock configuration is sometimes used to provide additionalsupport for the breast implant over time. Common materials for theinternal bra hammock are surgical mesh and decellularized tissue.

These internal bras provide additional support for the breast implant,but improved support and stabilization are still needed to ensurelong-lasting results in breast augmentation and reconstructionprocedures.

DRAWINGS

While the appended claims set forth the features of the presenttechniques with particularity, these techniques may be best understoodfrom the following detailed description taken in conjunction with theaccompanying drawings of which:

FIG. 1 is a top view of a mesh pouch configured in accordance with anembodiment.

FIG. 2 is a perspective close-up of an opening of the mesh pouch alongwith a drawstring.

FIG. 3 is a perspective rear view of the mesh pouch.

FIG. 4 is a rear view of the mesh pouch.

FIG. 5 and FIG. 6 depict a method for using the mesh pouch in surgery,according to an embodiment.

DETAILED DESCRIPTION

The disclosure is generally directed to a mesh pouch for securing animplant with a patient's body. According to various embodiments, themesh pouch includes a mesh wall that defines an enclosure having anopening. The mesh pouch further includes a drawstring configured toclose the opening when drawn so as to prevent the surgical implant fromleaving the enclosure. The mesh pouch may further include a mesh tabextending from the mesh wall, the mesh tab providing a surface forsuturing the mesh pouch to an inner surface of the patient's body. Themesh pouch may further include a strand extending from the mesh wall anda needle attached to a terminus of the strand. The strand may beconfigured to tighten the mesh wall around the surgical implant whenpulled.

The mesh pouch disclosed herein provides extra support andstabilization. After the implant is inserted into the mesh pouch and thetabs are sutured to the chest wall, the 360 degree mesh enclosure keepsthe implant localized for the duration of the healing process andalleviates the surrounding soft tissues of the weight of the implant.This latter benefit is particularly advantageous in post-mastectomybreast reconstruction, which is commonly performed in a setting oftenuous blood supply to the skin flaps that remain. The tabs on theoutside wall of the mesh pouch provide additional surface area to sutureand support the encased breast implant, without running the risk ofpuncturing the implant by suturing directly through the outer wall ofthe pouch. Compared to the hammock method, which only provides supportand localization in the cranio-caudal plane, the pouch method describedherein can fully bear the weight of the implant, force the implant intothe desired shape, and keep the implant localized medio-laterally.Further, it is more time-efficient to put an implant into a pre-shapedpouch, cinch it closed, and suture a small number of tabs in place thanit is to cut a custom hammock or sling out of a flat sheet, and thentailor it into the hemi-pocket of the appropriate size and shape for thegiven implant and soft tissue deficit.

Various embodiments of the mesh pouch include one or more drawstringsaround an opening, which can be pulled to close the opening. Using adrawstring design allows the walls of the mesh pouch to fit flushagainst an implant. This design helps to eliminate bunched up materialand resulting air pockets, which can cause bacterial infection, andswelling.

Embodiments of the mesh pouch described herein have no resorbablecoating. Instead, embodiments described herein are completelyconstructed of a bioabsorbable material. Having the entire deviceconstructed from a bioabsorbable material can cut down on complicationsand infections commonly seen from a non-bioabsorbable mesh implant.

The various embodiments described herein provide patients withlonger-lasting results from breast augmentation or reconstruction, whichreduces the need for subsequent revision surgeries.

Turning to FIGS. 1-4, a mesh pouch according to an embodiment isillustrated. The mesh pouch, generally labeled 100, includes a mesh wall102 that surrounds and defines an enclosure 104. The mesh wall 102 isspheroid in shape when fully expanded, but is configured to conform tothe shape of an implant when in use. The mesh wall 102 has an opening106 at an end 108, through which an implant (such as a breast implant orother mammary prosthesis, such as a tissue expander) may be inserted.

In an embodiment, the mesh wall 102 is made up of a first series ofcircular cords 110 that surround a longitudinal axis A of the mesh pouch100, and which are smallest in circumference at opposite ends 108 and112 of the mesh pouch 100 and largest in circumference around the center114 of the mesh pouch 100. The mesh wall 102 is further made up of asecond series of circular cords 116, which are oriented in planes thatare perpendicular to the planes of orientation of the first seriescircular cords 110. The mesh wall 102 is still further made up of athird series of circular cords 118, which are oriented in planes thatare perpendicular to the planes of orientation of both the first set ofcircular cords 110 and the second series of circular cords 116. Thesecond and third series of circular cords 116 and 118 are discontinuousin places where the opening 106 interrupts them.

In an embodiment, the mesh wall 102 comprises a porous material, such asknitted surgical mesh. It is configured to maintain a three-dimensionalconfiguration, such as a breast-shape or a sphere-shape, independent ofthe presence of a surgically-implanted device. It may be made of astretchable material that allows expansion of the opening 106 andsubsequent contraction of the opening 106 to or near its original size.The mesh wall 102 may be made of a bioabsorbable material such aspoly-(p)-dioxanone, poly-trimethylene-carbonate, polyglycolide, etc. Itmay also be composed of a biologic material. including complexextracellular matrices and simple polymers such as P4HB, fibroin, etc.It may also be composed of a permanent synthetic material such aspolypropylene, polyester, or expanded polytetrafluoroethylene.

In an embodiment, the mesh wall 102 incorporates a macroporous material(i.e., in which the pores are visible to the naked eye) that stronglyencourages tissue growth, localizing and shaping the implant. The degreeof porosity is one of the main determinants of tissue reaction.According to an implementation, the pores of the mesh wall extend overthe entire surface of the mesh wall and are greater than 70 μm(micrometers or microns) in diameter in order to facilitateneovascularization and neocollagenesis and to promote infiltration bymacrophages and fibroblasts. Such a macrophage and fibroblast responsefacilitates the tissue incorporation process and functional remodelingof implanted materials.

According to an embodiment, each of the pores of the mesh wall 102 is800 microns or greater in diameter. Having such a large pore sizefacilitates increased soft tissue ingrowth and avoids granulomabridging, which often leads to a stiff scar plate and reducedflexibility. This phenomenon often occurs in meshes with a pore size ofless than 800 μm.

In an embodiment, the mesh wall 102 is of a single-piece construction(i.e., not multiple wall pieces attached together).

According to an embodiment, proximate to and surrounding the opening 106is a drawstring 120 which, when pulled away from the mesh wall 102,closes the opening 106 sufficiently to prevent an implant from leavingthe enclosure 106. Turning to FIG. 2, the drawstring 120 is secured tothe mesh wall 102 by a sleeve 122 (which may be made of solid materialor may be made of a series of threaded loops). The drawstring 120 has afirst free portion 124 and a second free portion 126, each of which isfree from the sleeve 122. In order to close the opening 106, one or bothof the free portions 124 and 126 are pulled away from the mesh wall 102.Instead of a sleeve 122, the drawstring 120 may be attached to the meshwall 102 via one or more openings along the edge of the opening 106(e.g., sufficiently dimensioned so that a cord or string can be passedthrough and pulled to close the opening of the pouch in a drawstring orpurse string fashion).

In an embodiment, material around the opening 106 has elastic propertiesconferred by the textile characteristics of the mesh wall 102 (e.g., atthe rim of the opening) such that a surgical implant may be placed inthe enclosure 106 by forcibly widening opening and inserting theimplant. The implant is then trapped by the retraction of the opening.This embodiment may or may not include a drawstring.

As shown in FIGS. 1-4, in an embodiment, the mesh pouch 100 includes oneor more extensions, shown in the figures as a first mesh tab 128 and asecond mesh tab 130. The mesh tabs 128 and 130 are attached to the meshwall 102 on opposite sides of the widest point of the mesh pouch 100.The mesh tabs 128 and 130 provide surfaces for suturing the mesh pouch100 to interior portions (e.g., internal tissue) of a patient. The poresizes and pattern of the mesh tabs may vary depending on the embodiment.Two mesh tabs are shown in the drawings, but additional mesh tabs arepossible in other embodiments. In this embodiment the mesh tabs 128 and130 are placed on the same plane halfway (or approximately halfway)through the cross of the spheroid shape of the mesh pouch 100. Otherembodiments may have the mesh tabs placed on different planes or atdifferent cross-sectional lengths along the diameter of the mesh pouch.

In an embodiment, the mesh pouch 100 includes an integrated strand 132attached to the mesh wall 102. The strand 132 has a needle 134 attachedto its terminus. The strand 132 may be used to suture the mesh pouch 100to an interior portion of a patient. According to an embodiment, thestrand 132 is connected to one or more of the cords of the mesh wall 102(either with a sleeve configuration such as the drawstring 120 orwithout a sleeve) so that pulling the strand 132 (e.g., while suturingusing the strand) has the effect of making the enclosure 104 smaller sothat the mesh wall 102 fits more snugly onto an implant. The mesh pouch100 may have multiple such integrated strands with needles.

Turning to FIG. 5 and FIG. 6, an example of how the mesh pouch 100 isused will now be described. A medical device, such as a breast implantis inserted into the mesh pouch 100 through the opening 106. After themedical device is inserted it will be fully encased inside the mesh wall104. The drawstring 120 is pulled such that the opening 106 becomesincreasingly small as the drawstring 120 is pulled tighter until it istight. The drawstring 120 is then cinched. The implant may be heldwithin the mesh pouch 100 due to the elastic recoil of the mesh wall102, or more firmly by closure of opening 106 with the drawstring 120.The resting shape of the mesh wall 102 may force a round implantenclosed in this way to take on a more natural breast shape.

The implant within the mesh pouch 100 can then be placed in theappropriate position and appropriate tissue plane as it would be withoutthe mesh pouch 100 (between the skin and the pectoralis/fascia in thesetting of prepectoral breast reconstruction, for example). However,after placement, the integrated mesh tabs 128 and 130 can be sutureddirectly to the soft tissue (an interior the chest wall or other tissue,such as the pectoralis fascia, for example) in order to maintain itsposition during the healing process. The suturing of the mesh pouch 100to the chest wall provides a way to localize the implant without havingto rely on soft tissue manipulation, and the position of the tabsdistant from the breast prosthesis minimizes the risk of accidentaldamage to the breast prosthesis during this process. Positioning andshaping may be further facilitated by the use of the integrated needle134 (or needles, if there are multiple) to suture to the chest wall,which (if integrated with the mesh wall 102 as described above) alsocinches down or tailors the mesh pouch 100 as desired by the tighteningof strands (e.g., integrated fibers) to which the integrated needles areattached. Finally, the overlying layers (skin and subcutaneous tissue,for example), are closed. The weight of the implant is borne by the meshpouch 100 and the soft tissue to which it is sutured, rather than theskin envelope that is covering it.

According to an embodiment, the mesh pouch 100 is formed as follows: 1)A mesh sheet is formed by warp knitting, electrospinning, or othertextile technique. 2) A thermally conductive mold or mandril is formedin a desired spheroid or breast shape. 3) The mesh is wrapped around andannealed to the mold or mandril to the desired spheroid or breast shape.

The mesh pouch 100 may have uses in multiple domains of breast surgery,such as direct-to-implant, prepectoral, breast reconstruction for amastectomy defect. In this setting, recreation of the breast mound isperformed by placing a prosthetic breast implant in the plane betweenthe pectoralis muscle and the overlying skin, in the space where breasttissue used to reside prior to the mastectomy. For example, in FIG. 5,there is depicted a mesh-pouched implant 500 (configured according toone or more of the previously described embodiments) disposed in situ ina human breast, with a retractor 502 also shown. In FIG. 6, there isdepicted a mesh-pouched implant 600 (configured according to one or moreof the previously described embodiments) disposed in situ in a humanbreast with a mesh tab 602 sutured in place. The various tissue shown inFIG. 6 includes skin and subcutaneous tissue 604, pectoralis 606, ribs608, and intercostals 610.

It should be understood that the embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. It will be understood by those ofordinary skill in the art that various changes in form and details maybe made therein without departing from their spirit and scope.

What is claimed is:
 1. A mesh pouch for holding a surgical implantwithin a patient's body, the mesh pouch comprising: a mesh wall thatdefines an enclosure having an opening at an end of the enclosure, themesh wall comprising a plurality of pores, wherein each of the pluralityof pores is at least 70 microns in diameter; and a drawstring disposedat a rim of the opening, wherein the drawstring configured to close theopening when drawn so as to prevent the surgical implant from leavingthe enclosure.
 2. The mesh pouch of claim 1, wherein each of theplurality of pores is at least 800 microns in diameter.
 3. The meshpouch of claim 1, further comprising a strand extending from the meshwall.
 4. The mesh pouch of claim 3, further comprising a needle attachedto a terminus of the strand.
 5. The mesh pouch of claim 1, furthercomprising one or more strands extending from the mesh wall, whereineach of the one or more strands is configured to tighten the mesh wallaround the surgical implant when pulled.
 6. The mesh pouch of claim 1,wherein the enclosure is spheroid in shape when the mesh wall is fullyexpanded.
 7. The mesh pouch of claim 1, wherein the mesh wall is made ofa stretchable material that allows the expansion and contraction of theopening.
 8. The mesh pouch of claim 1, wherein the mesh wall is made ofa material selected from a group consisting of poly-(p)-dioxanone,poly-trimethylene-carbonate, polyglycolide, P4HB, and fibroin.
 9. Themesh pouch of claim 1, wherein the mesh wall is made of a permanentsynthetic material.
 10. The mesh pouch of claim 9, wherein the permanentsynthetic material is polypropylene, polyester, or expandedpolytetrafluoroethylene.
 11. A mesh pouch for holding a surgical implantwithin a patient's body, the mesh pouch comprising: a mesh wall thatdefines an enclosure having an opening that, when closed, prevents thesurgical implant from leaving the enclosure, the mesh wall comprising aplurality of pores, wherein each of the plurality of pores is at least70 microns in diameter; and a strand extending from the mesh wall,wherein the strand is configured to tighten the mesh wall around thesurgical implant when pulled.
 12. The mesh pouch of claim 11, furthercomprising a needle attached to a terminus of the strand.
 13. The meshpouch of claim 11, wherein each of the plurality of pores is at least800 microns in diameter.
 14. The mesh pouch of claim 11, furthercomprising a drawstring configured to close the opening when drawn so asto prevent the surgical implant from leaving the enclosure.